Laser line generating device

ABSTRACT

A self-contained line generating device uses a laser diode and a lens to project a fan-shaped beam of visible light. The lens is useful for receiving light and transmitting light in an asymmetrical planar beam. The light is useful for aligning objects in a vertical or a horizontal line. The generator also includes a substantially flat face and leveling devices for leveling and orienting the generator onto a flat surface. Retractable pins enable a user to easily mount the line generator onto a wall and align objects.

CLAIM TO PRIORITY

[0001] This application claims priority under 35 U.S.C. § 111(b) to thefiling date of U.S. Provisional Application 60/291,135, May 15, 2001, ofthe same title, which is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] Alignment of surfaces is a perennial problem in a variety offields, ranging from construction to interior decorating. Alignment isnecessary for walls that should be perpendicular to a floor, orotherwise plumb. Masonry and brick-laying practitioners are well awareof the importance of plumbed and aligned surfaces and chalk lines. Ahome interior decorated with pictures and other wall ornamentation makesa much better appearance when the ornamentation is aligned, especiallywith respect to vertical or horizontal alignment. Many mechanical andelectrical alignment devices are available, and some laser devices areavailable. Some of these products are cumbersome, others are not asuseful as they could be. Chalk lines, for instance, are sometimesundesirable for use in finished, interior areas.

[0003] One aspect of alignment-product performance, and in particular oflaser-alignment products, that could be improved is the width,brightness and straightness of the laser light. A visible, straightlaser line is acceptable, but may be limited in its brightness over adistance, and may also tend to defocus and become dimmer as a user worksaway from the source of the laser. Rotating lasers are used to projectlines on walls perpendicular to the direction of propagation of thelaser. Thus, such devices may have limited utility or may not work inconfined spaces requiring a longer alignment tool.

[0004] Moreover, a conventional laser is not well-equipped forprojecting a flat or planar beam of light. The essence of laser light isthat it is coherent or substantially monochromatic, that is, of a singlewavelength or a narrow wavelength band. Thus, when a beam of laser lightis refracted through a prism, the prism output is not a spreading of thebeam as with ordinary “white” light, but rather a coherent, focusedbeam, very similar to the input. The laser beam is thin and is usefullyonly visible when projected onto a surface.

[0005] Another aspect that could be improved is the inability of laserdevices to work around obstructions. That is, if a wall-hanging, such asa picture frame, interrupts the laser beam, it may be blocked fromfurther projection. Therefore, it is necessary to mark locations orheights, one by one, rather than working with the actual objects, inorder to align them. Obstructions may include moldings placed in adoorway, picture frames in the way of those being aligned on onehorizontal line, the operator of the device, other obstacles, or eventextured or stuccoed surfaces on interior walls.

[0006] There are devices that direct a laser beam parallel to but awayfrom a surface requiring alignment. A marker device or detectorcomponent is then used to sight the beam and mark correspondinglocations on the wall adjacent the beam. Use of such a device requiresmultiple components and at least two people, one to align the laser andanother to mark the wall. Moreover, the wall itself requires markingwith this method.

[0007] A conventional laser beam projector is thus not able to project alaser line on the wall on which it is mounted, nor can it go aroundobstructions. A laser alignment beam mounting on the wall wherealignment is needed would allow a person seeking alignment, whether acarpenter, a painter, or an interior decorator, to accomplish his or hertask in a quicker and easier fashion. The ability to work aroundobstacles would save much time and effort. Finally, such laser alignmentdevices must be aligned themselves, and are typically equipped with atripod and a sophisticated leveling device so that they read true forhorizontal and vertical plumbs. While leveling is necessary, suchsophistication as a tripod adds to the expense and bulkiness of theleveling device. What is desired is a convenient, easy-to-level laserdevice useful for aligning objects.

BRIEF SUMMARY OF THE INVENTION

[0008] One embodiment of the invention is a laser line generatingdevice. The line generating device includes a housing. Within thehousing are mounted a light source and a power supply connected to thelight source. There is a projection lens that receives light andprojects the light in the shape of a fan. There is also at least onereference level on an outside of the housing. The light is projectedsubstantially along its direction of propagation onto the wall on whichit is mounted. Another embodiment is a line generating device. The linegenerating device includes a housing and a light source mounted withinthe housing. There is a power supply connected to the light source, andthere is a projection lens that receives light and projects the light ina direction of propagation in the shape of an elongated fan thatsubstantially lies within a plane that is oriented at an angle withrespect to the direction of propagation.

[0009] Another embodiment is a method for projecting a fan-shaped laserlight onto a surface. The method includes focusing a light into a fanshape that substantially lies within a plane, and projecting thefan-shaped light in a direction of propagation that is oriented at anangle with respect to the plane. Another embodiment is a line generatingdevice. The line generating device includes a housing and a light sourcemounted within the housing. Within the housing there is also an opticalsystem that receives light and projects the light as a fan-shaped beamthat lies substantially within a plane and forms a visible line at anintersection of the beam and a surface of interest. Another embodimentis a lens for receiving and projecting light. The lens includes anoptical material, and has at least one corner radiused from about 0.030to about 0.060 inches. The lens is adapted to receive light and totransmit light in a fan-shaped beam.

[0010] The following drawings form part of the present specification andare included to further demonstrate certain aspects of the presentinvention. The invention may be better understood by reference to one ormore of these drawings in combination with the detailed description ofspecific embodiments presented herein.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0011]FIG. 1 is an isometric view of an outside of an embodiment of alaser line generator according to the present invention.

[0012]FIG. 2 is an alternate view of the generator of FIG. 1.

[0013]FIG. 3 is a cutaway isometric view showing the inside of thegenerator of FIG. 1.

[0014]FIG. 4 is a view depicting the bottom of the generator of FIG. 1.

[0015]FIG. 5 is another view depicting the bottom of the generator ofFIG. 1.

[0016]FIG. 6 depicts an embodiment of optics to be used with the laserlight generator of FIG. 1.

[0017]FIG. 7 depicts a side view of the workings of a second embodimentof laser light generator optics to be used with the laser line generatorof FIG. 1.

[0018]FIG. 8 depicts a top view of the workings of the laser lightgenerator optics of FIG. 7.

[0019]FIGS. 9A and 9B depict a laser line generating device projectingthe laser light in a narrow beam or fan and aligning objects on a wall.

[0020]FIGS. 10 and 11 depict lens geometries useful for lenses in thepresent invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0021] The present invention-is better understood by reference to thefigures and description below. FIG. 1 presents a view of a laseralignment device and generator 10. The generator comes in a housing 12,which may be made of plastic or other suitable material such as metal.It possesses a handgrip area 14 for handling, the area preferably madeof an elastomeric substance for easier gripping. The generator has afirst leveling device 16, a spirit level or “bubble” for orientation orleveling in one plane, such as horizontal or vertical. It also has asecond leveling device 18, for orientation or leveling in a second planeperpendicular to the first plane. The housing also contains a protectivedoor 20 with a linked switch for turning on the laser light source whenopening the door for access to the laser beam. The generator also mayhave one or more sliding levers 22 suitably mechanically connected forextending or retracting one or more pins 26 from the generator bottom28. Each pin desirably penetrates into a surface, such as a drywall orlumber surface, to suspend and hold the laser generator on the surfacewhile it is in use. FIG. 1 depicts the door 20 in an open position and aprojection lens 24. The door or aperture 20 provides an exit for thelight generated within the housing, and in the open position, does notsubstantially block the exit of light from the housing.

[0022] As shown in FIG. 1, a preferred projection lens 24 includes arounded corner 25 on its front face 27. The effect of the lens is toshape the laser light into a planar, fan-shaped “comet beam” or fanshape. The intensity of the light and the shape of the beam may beasymmetric, in which one side of the “comet” may be larger and brighterthan the other side. The fan shaped beam is then routed so that the lessbright side of the lens is nearest the wall of interest, and thebrighter side is away from the wall. In this orientation, the fan-shapedbeam of light will propagate a long distance from its origin, and thelaser light will be usable a long distance away from the laser linegenerating device.

[0023] The laser light generated by the laser line generator preferablyexits from the top, curved corner of the lens. The radius of the corneris desirably from about 0.030 inches (0.75 mm) to about 0.060 (1.50 mm)inches, and preferably about 0.047 inches (1.2 mm). The height of therounded corner of the lens is desirably one or two inches above thebottom surface of the laser line generating device. When the beam or fanof light exits the lens, it forms a thin plane in the length-wisedirection of the device, and the beam forms a plane from the top, curvedcorner of the lens downward, to the wall or other surface on whichalignment is sought. Because the light is now a plane, rather than athin pinpoint, it is able to project over and beyond obstacles, allowinga user to align several objects without having to move them.

[0024] In the embodiments shown, the laser light projects in thedirection of the alignment surface, a generally flat, planar bottomsupport surface. The direction of propagation is the direction the lighttravels, generally parallel to the wall on which the laser linegenerating device is mounted. The fan-shaped aspect of the beam isperpendicular to the wall, and is preferably no higher than the heightof the lens 24 above the wall. The laser light generating device and itslens are mounted on the wall, and the fan-shape of the beam extends froma height of the lens above the wall to the wall surface itself, in avery thin plane, about {fraction (1/32)} of an inch thick. The plane ofthe fan-shaped beam is also perpendicular to the flat bottom surface ofthe laser line generating device.

[0025]FIG. 2 depicts the same device with the door 20 closed, and with alinked internal switch (not shown) open, and the laser thus off. Thefigure depicts the generator 10, housing 12, gripping surface 14 andlevels 16, 18 with pin lever 22 raised so that the pin remains insidethe housing and the laser generator is not suspended on a wall or othersurface. The door or aperture 20 may also be a switch for the powersupply of the laser line generating device. In the position shown inFIG. 2, with the door closed, the switch is preferably in a closedposition and there is no power supplied from the power supply to thelight source. In this position, the door acts as a lens cover andsubstantially blocks the exit of the device.

[0026]FIG. 3 depicts a cutaway view of the interior of the lasergenerator, showing a supporting structure 34 for levels 16, 18, and alsoshowing an area for a power source or battery 32, a laser diode 42, alens 24, and a circuit board 36. FIG. 4 more clearly depicts a view fromthe bottom or flat face 30 of the generator 10. The bottom surfacedesirably has a door 52 for access to a battery or power source for thegenerator. Also shown are holes 54 for the retractable pins 26 used tosecure the generator to a wall or a surface. A notch 56 may also beuseful for aligning or orienting the generator on a surface. FIG. 5depicts the bottom of the laser generator with the pins retracted, witha better view of holes 54.

[0027] A method of practicing the invention includes providing asurface, such as a wall wherein orientation with a line is desired, andalso providing the laser generator. A user mounts the laser generator 10via its flat surface and one or more pins onto the wall and orients itin one or more planes, depending on the number of pivot points and onthe number of reference levels provided on the generator. Typically, auser will mount the generator 10 with a pin or retainer placed through apivot point on the flat surface of the generator. The reference levelsuch as the bubble level 18 is then used to orient and true thegenerator in one plane, for instance, the vertical plane. The secondbubble level 16 may be used if the user wishes to orient the generatorin a horizontal plane. When the user is satisfied with the orientation,the user turns on the generator 10, projecting a laser beam from thevertical or horizontal plane of the device. In one embodiment, thegenerator is turned on by opening the lens door or aperture. In additionto the retractable pins used as pivot point, the device may haveapertures or holes placed in the flat bottom surface. In this method, auser inserts pins or nails through the holes and mounts, levels, andsupports the laser generator using those pins.

[0028] A desirable feature of the invention is that the output of thegenerator is not merely a linear beam of light, but rather a fan-shapedbeam. The fan-shaped beam propagates along the surface of the wall inthe direction of propagation. Because the plane of the beam runsperpendicular to the wall along the length of the beam, the line ofintersection between the beam and the wall forms a visible line ofalignment. With a fan-shaped beam, the laser light is able to projectover and beyond obstacles, such as moldings placed in a doorway, pictureframes in the way of those being aligned on one horizontal line, orother obstacles, such as a wavy or stuccoed surface on an interior wall.With a conventional laser generator, these obstacles must be removed orthe laser itself must be repositioned to avoid each obstacle. Of course,moving and relocating the laser alignment tool destroys the continuityof the line of alignment. Moreover, a conventional laser is notwell-equipped for shaping the laser beam into a fan. The essence oflaser light is that it is coherent, that is, of a single wavelength or anarrow wavelength band. Thus, when laser light is refracted through aprism, the prism output is not a spreading of the beam as with ordinary“white” light, but rather a coherent, focused beam, very similar to theinput. The present invention overcomes this obstacle by sending a sharp,focused pinpoint of light through a specifically constructed lens tocreate a flat planar, fan-shaped beam of light.

[0029] It is also noteworthy that the axis of alignment, such as thealignment of pictures on a wall, is substantially parallel to thedirection of propagation of the laser light. By contrast, a conventionaland less useful method is to project a laser light perpendicular to awall or other surface in which alignment is desired, and perpendicularto the direction of propagation. With the instant laser line markingdevice, a user projects a fan-shaped beam in a propagation directionthat is substantially parallel, rather than perpendicular, to thesurface on which alignment is desired, the fan-shaped dimension of thebeam being perpendicular to the wall.

[0030] As seen in FIG. 9a, the laser line generating device propagateslight in the length-wise direction of the laser line generating device10. The direction of propagation, shown by arrow 84, is substantiallyparallel to the wall, with the fan-shaped aspect of the beam beingperpendicular to the wall. In one example, if a narrow fan projects froma line marking device according to the present invention, the beam is“substantially parallel” if it is substantially parallel for at leastseveral lengths of the line marking device in the direction ofpropagation of the laser. It is substantially parallel because even a“narrow” fan spreads rapidly and the beam is no longer strictlyparallel. The device and the beam are easily distinguished, however,from a beam that has a direction of propagation perpendicular to thewall, such as shown in U.S. Pat. No. 5,208,438.

[0031] The laser light exits the lens or prism in an elongated fan in adirection of propagation. The direction of propagation, as discussedabove, is substantially parallel to the surface on which alignment isdesired. The width of the fan, however, is perpendicular to the surface,and the intersection of the beam with the surface generates the visibleline of alignment that the user seeks. It is this width that allows thefan to project over and beyond obstacles. That is, even though anobstacle may partially obscure the fan-shaped beam of light, at leastpart of the fan-shaped beam extends above and beyond the obstacle, and auser may continue to align objects on which alignment is desired.

[0032]FIG. 6 depicts an embodiment of the invention, in which a laserdiode 60 emits coherent laser light, such as, coherent laser light at635 nm wavelength. The light is collimated into an ovate shape bycollimation optics 62, for instance at least one collimating lens, bytechniques well known to those skilled in optic arts. The ovate beamthen enters a projection lens 64 from the right side in FIG. 6,desirably at an angle in which total internal reflection will occur,that is, all the incident light will be reflected rather than refractedfrom the back face of the lens. It has been found that this phenomenonis reinforced further if the back surface 66 of the lens is mirrored.The phenomenon is also reinforced if a corner of the lens or prism isradiused as mentioned above. When the light emerges from the radiusedcorner 65 of the projection lens 64 in FIG. 6, it is in the shape of anarrow beam or fan, rather than a single point or beam of light, and isable to extend around and beyond obstacles for the convenience of auser. In one embodiment of the invention, the angle A between the mirrorsurface of the collimating lens and the incident light from the laserdiode source is from about 60 to about 65 degrees, preferably about 63degrees, for maximum reflection of light through the lens, rather thanrefraction at angles that detract from the performance of the generator.In this depiction, the light 68 is planar within the plane of the paper,when it leaves the lens. In one embodiment of the invention, the laserdiode, the collimation lens, and the projection lens are containedwithin a single element, such as a laser diode with included collimatingoptics.

[0033] In one embodiment shown in FIG. 6, an aspherical projection lensis made from optic grade glass, in the form of an equilateral trianglewith the back face mirrored. Desirably, the lens is about 0.45 inches ona side, with one corner 65 radiused to about 0.030 to about 0.060 inchesand the other corners rounded to a radius of 0.005 to 0.015 inches. Withthis geometry, the lens or prism is able to focus an incoming ovate beaminto a planar, thin, fan-shaped beam that is useful for aligningobjects.

[0034]FIG. 7 depicts a side view of another embodiment of the invention,in which a laser light source 70, such as a laser diode, emits laserlight, which is collimated into an ovate shape by collimating optics 72and then sent to an aspherical projection lens 74 with one corner 75radiused as mentioned above for projection of a narrow fan of light 76.In one embodiment, the axes of the ovate-shaped beam sent to the lensare about {fraction (3/16)} inches by about {fraction (1/16)} inch. Theplanar, fan-shaped beam 76 emerging from projection lens 74 is thanabout {fraction (1/32)} inch thick. Note that the top corner 75 on theface of the lens in FIG. 7 is radiused from about 0.030 to about 0.060inches, and preferably about 0.047 inches. FIG. 8 depicts the sameembodiment in a top view, in which the rounding may not be observable.The source of laser light 70 generates visible laser light and thecollimating optics 72 shape the light into a narrow beam. From the topview, the beam of light is very thin and is about the width of theprojection lens 74, 0.4 inches wide. From the side view, the projectedlight is a thin beam; from the top view, the projected light is a thinfan.

[0035] One embodiment of the invention features a lens, such as thelenses depicted in FIG. 7 and 8, that is about 0.4 inches (10 mm)square, and about 0.1 inches thick (2.5 mm) in the direction ofpropagation, that is able to focus the incoming laser light beam andreflect it into a planar fan shape. The lenses are aspherical,cylindrical lenses. The lens may be made from one of severaloptical-grade clear, highly transparent materials, including BK7 glasshaving an index of refraction of about 1.5168 and a Vd of 64.17. Inanother embodiment, acrylic resin having an index of refraction of1.4917 and a Vd of about 55.31 is useful. It has been found that thelens works better if the exit face has only one corner radiused about0.047 inches, with the other faces being radiused for normalmanufacturing custom, to about 0.005 to about 0.015 inches.

[0036]FIG. 9A demonstrates the use of an embodiment of a laser generator10 according to the present invention, in which a fan-shaped beam 76 isable to align a first picture frame 78 on wall 77. The generator isconvenient to use because it projects a laser beam on the wall adjacentthe generator. The beam is able to overcome obstacles such as doormoldings 80 with its fan shape and extend above the molding withsufficient clarity to align another object, such as picture frame 82. Itis able to overcome these obstacles because the corner from which thelight exits is one or two inches removed or offset from the wall,allowing a fan or beam of light to form. The direction of propagation 84is in the direction from the generator to the objects on which alignmentis desired, such as picture frames. At the same time, the width of thefan is perpendicular to the wall 77 on which the paintings are hung oron which, more generally, alignment is desired. The fan-shaped beam 76intersects the wall 77 and the light is visible on the wall at theintersection 79 of the fan-shaped beam 76 with the wall 77. In oneembodiment, the housing of the laser line generator is a support facethat substantially extends along a first planar surface, such as wall77, and the fan shaped beam 76 substantially lies within a second planarsurface, such as the plane of light 76. The second planar surface mayintersect the first planar surface at an angle. The angle may preferablybe 90°, or a right angle between the fan-shaped beam and the surface onwhich objects are to be aligned.

[0037] The “comet” effect means that the intensity of the planar fan isless nearer the wall and greater away from the wall, so that the beam isable to usefully travel further, and enable a user to align objects atgreater distances. Thus, in the embodiment shown in FIG. 9B, theintensity of the laser light will be greater at outer edge 87 than atthe inner edge 85 where the fan-shaped beam intersects the wall 77 whilethe beam is used to align object 82, such as a picture frame. There isno practical limitation to the distance the fan-shaped beam can travel.Laser diodes of 5-15 mW can be successfully used to project beams 30-50feet long along painted wall-board surfaces. In one embodiment, thefan-shaped beam is projectable as a visible line extending at leastabout 5 lengths of the housing away from the housing for aligningobjects.

[0038]FIGS. 10 and 11 depict geometries of projection lenses that can beuseful in connection with this invention. FIG. 10 depicts the sag orcurvature of the exit face of the lens (z-direction deviation plottedagainst the depth or y-coordinates of the lens), while FIG. 11 depictsthe overall profile or curvature of the lens surface. While theseparticular embodiments work well, the invention is not limited to theseembodiments, and other embodiments will also suffice.

[0039] While this invention has been shown and described in connectionwith the preferred embodiments, it is apparent that certain changes andmodifications, in addition to those mentioned above, may be made fromthe basic features of this invention. For instance, lenses may be madefrom glasses other than BK7 and plastics other than acrylic, so long atthey are transparent and to a degree sufficient to be used as a lens orarticle for transmitting light. While embodiments of triangular prismsand relatively flat square lenses have been successful, other polygonsor aspherical embodiments may also be used, so long as they have aradiused corner of about the requisite dimension. In other embodimentsof a laser generating device, alignment may be made in lines or planesthat are diagonal, rather than horizontal or vertical. While one or morepins may be used to hold the generator onto a wall, other devices may beused as retainers. These devices include, but are not limited to, astring or a wire, a fastener, tape, putty-type substances or otheradhesives. While the laser line generator may be most convenient to usewhen pinned to a wall, it may also be mounted on a table, floor, orother flat surface, and used to project a line without being mounted ona wall. Many other variations of our invention may also be used withoutdeparting from the principles outlined above. Accordingly, it is theintention of the applicants to protect all variations and modificationswithin the valid scope of the present invention. It is intended that theinvention be defined by the following claims, including all equivalents.

What is claimed is:
 1. A line generating device, comprising: a housing;a light source mounted within the housing; a power supply connected tothe light source; a projection lens that receives light and projects thelight in the shape of a fan; and at least one reference level on anoutside of the housing.
 2. The device of claim 1, wherein the lightsource generates a laser beam.
 3. The device of claim 2, wherein thelaser beam has an asymmetric intensity pattern.
 4. The device of claim1, wherein the housing comprises a support face that substantiallyextends along a first planar surface and the fan substantially lieswithin a second planar surface that intersects the first plane surfaceat an angle.
 5. The device of claim 4, wherein the angle is about 90°.6. The device of claim 4, further comprising at least one pivot point onthe support face.
 7. The device of claim 5, wherein the at least onepivot point comprises a retractable pin.
 8. The device of claim 7,further comprising a lever for pushing and holding the retractable pininto a surface.
 9. The device of claim 6, wherein the at least one pivotpoint further comprises an opening in the support face.
 10. The deviceof claim 4, wherein the light projects a line in a direction generallyparallel to the first planar surface, the line extending in a directionof propagation of the light.
 11. The device of claim 1, wherein thepower supply is a battery mounted within the housing and switchablyconnected to the light source.
 12. The device of claim 1, wherein the atleast one reference level comprises a bubble level.
 13. The device ofclaim 1 wherein the at least one reference level comprises two bubblelevels oriented at right angles to each other.
 14. The device of claim1, further comprising an aperture in the housing.
 15. The device ofclaim 1, wherein a corner of the lens has a radius of about 0.030 inchesto about 0.060 inches.
 16. The device of claim 15, wherein the corner ofthe lens has a radius of about 0.047 inches.
 17. The device of claim 1,wherein the light in the shape of a fan is projectable as a visible lineextending at least about 5 lengths of the housing from the housing. 18.The device of claim 1, further comprising a collimating optics thatreceives light from the light source and focuses the light into an ovateshape for the projection lens.
 19. The device of claim 1, wherein theprojection lens is made from glass or plastic.
 20. A line generatingdevice, comprising: a housing having a face and a closable aperture; alight source mounted within the housing; a battery switchably connectedto the light source; a lens that receives light and projects the light;at least two pivot points on the face of the housing; and at least twobubble levels at right angles to each other on an outside of thehousing.
 21. The device of claim 20, wherein the light source generatesa laser beam.
 22. The device of claim 20, wherein the lens projects thelight in the shape of a fan.
 23. A line generating device, comprising: ahousing; a light source mounted within the housing; a power supplyconnected to the light source; and a projection lens that receives lightand projects the light in a direction of propagation in the shape of anelongated fan that substantially lies within a plane that is oriented atan angle with respect to the direction of propagation.
 24. The device ofclaim 23, wherein the angle is about 90°.
 25. The device of claim 23wherein the light source comprises a laser.
 26. The device of claim 23wherein the direction of propagation is generally parallel to analignment surface on the housing.
 27. The device of claim 23 furthercomprising a collimating optics that receives light from the lightsource and focuses the light into an ovate shape for the projectionlens.
 28. The device of claim 23, further comprising at least one pivotpoint on the housing, and at least one reference level on an outside ofthe housing.
 29. The device of claim 23, further comprising an aperturein the housing, the aperture providing an exit for the light and a coverswitchably connected to the power supply, wherein when the cover movesto a first position the light source is connected to the power supplyand the lens cover does not substantially block the exit and when thecover moves to a second positions the light source is not connected tothe power supply and the lens cover substantially blocks the exit. 30.The device of claim 23, wherein the power supply is a battery.
 31. Thedevice of claim 28, wherein the at least one reference level comprisesat least one bubble level mounted at right angles to any other bubblelevels.
 32. The device of claim 23, further comprising a lever forpushing and holding a pin.
 33. The device of claim 23, wherein a cornerof the projection lens has a radius of about 0.030 inches to about 0.060inches.
 34. The device of claim 33 wherein the corner of the projectionlens has a radius of about 0.047 inches.
 35. The device of claim 23,wherein the fan-shaped beam has an asymmetric intensity pattern.
 36. Thedevice of claim 23, wherein the projection lens is made from glass orplastic.
 37. A method for projecting a fan-shaped laser light onto asurface, the method comprising: focusing a light into a fan shape thatsubstantially lies within a plane; and projecting the fan-shaped lightin a direction of propagation that is oriented at an angle with respectto the plane.
 38. The method of claim 37, wherein the direction ofpropagation is oriented at about 90° with respect to the plane.
 39. Themethod of claim 37, wherein the light is substantially monochromatic.40. The method of claim 37, further comprising forming a line on asurface of interest.
 41. The method of claim 40 further comprisingpivoting the fan-shaped light onto the surface of interest.
 42. Themethod of claim 37 further comprising orienting and leveling thefan-shaped light.
 43. A lens for receiving and projecting light, thelens comprising: an optical material; and at least one corner radiusedfrom about 0.030 to about 0.060 inches; wherein the lens is adapted toreceive light and transmit light in a fan-shaped beam.
 44. The lens ofclaim 43, wherein the at least one corner is radiused about 0.047inches.
 45. The lens of claim 43, wherein the fan-shaped beam has anasymmetrical intensity.
 46. The lens according to claim 43 wherein theoptical material is glass or plastic.
 47. The lens according to claim43, wherein the lens is aspherical.
 48. A lens according to claim 47,wherein the shape of the lens is selected from the group consisting of aprism, a flat rectangle, a flat square and a flat polygon.
 49. A linegenerating device, comprising: a housing; a light source mounted withinthe housing; and an optical system that receives light and projects thelight as a fan-shaped beam that lies substantially within a plane andforms a visible line at an intersection of the beam and a surface ofinterest.
 50. The line generating device of claim 49, wherein the lightis substantially monochromatic.
 51. The line generating device of claim49, wherein the optical system comprises at least one lens that receiveslight from the source and focuses and projects the light.
 52. The laserline generating device of claim 49, the housing further comprising asubstantially flat face and at least one pivot point comprising aretractable pin on the substantially flat face.
 53. The laser linegenerating device of claim 49, further comprising at least one bubblelevel.
 54. A line generating device, comprising: a housing having atleast one retractable pin mounted on a substantially flat face of thehousing; a light source mounted within the housing; and a power supplyconnected to the light source.
 55. The device of claim 54, furthercomprising at least one lens that receives light from the light source.56. The device of claim 54, further comprising at least one lens thatreceives light from the light source.
 57. The line generating device ofclaim 54, wherein the light source comprises a laser light source. 58.The line generating device of claim 56, wherein the at least one lensthat receives light from the light source projects the light as afan-shaped beam.
 59. The line generating device of claim 54, furthercomprising at least one reference level on the housing.
 60. A method ofaligning an object with a light beam, the method comprising: generatinglight along a direction of propagation so that a line is formed along afirst planar surface, wherein the line is interruptible in that shouldan impediment be positioned on the line, the line will be present oneither side of the impediment; and placing an object so that a portionof the object is aligned by the light.
 61. The method of claim 60,wherein the method generates light in the shape of a fan that liessubstantially in a second planar surface that intersects the firstplanar surface at an angle.
 62. The method of claim 61, wherein theangle is about 90°.
 63. The method of claim 60, further comprisingfocusing the light into a fan-shaped beam offset from the surface by adistance.